Patent Literature 1 discloses a glass panel unit where spacers are sandwiched between a pair of plates of glass. Patent Literature 1 discloses a manufacturing method including placing spacers which are made to have a solid cylindrical shape in advance, on a plate of glass (glass substrate) in a predetermined arrangement. Placed on the plate of glass where the spacers are placed, is another plate of glass (glass substrate), thereby a glass panel unit where the spacers are sandwiched between the pair of plates of glass being obtained.